Classes, Inheritance - Stupid lazy question

Michael Scharf Michael.Scharf at gmx.de
Thu Apr 13 03:36:05 CEST 2000


Michael Hudson wrote:
> another option is:
> 
> class paul(lazy):
>     super = lazy
>     def __init__(self, name):
>         self.super.__init__(self,name)
>         self.april_pay = 0
> 
>     def fired(self):
>         print "Here's a box, collect the things from your desk"
>         self.super.fired(self)
> 
> Though this has problems with repeated & multiple inheritance.

What happens if you want to inherit from paul? 
self.super would be overwritten!

Make super private (__super) and it will work fine. 

We use a similar trick in C++ (a private <typedef MySuperClas super>),
so changing the superclass requires only two changes in the header...

#---snip---

class lazy:
    def __init__(self, name):
        self.name = name

    def fired(self):
        print 'You are fired %s!' % self.name

class paul(lazy):
    __super=lazy
    def __init__(self, name):
        self.__super.__init__(self,name)
        self.april_pay = 0

    def fired(self):
        print "Here's a box, collect the things from your desk."
        self.__super.fired(self)

class michael(paul):
    __super=paul
    def fired(self):
        print self.name, "will fire paul!"
        self.__super.fired(self)

lazy("lazy").fired()
print
paul("paul").fired()
print
michael("michael").fired()

#---snap---

Michael
-- 
     ''''\     Michael Scharf
    ` c-@@     TakeFive Software GmbH, a Wind River Company
    `    >     http://www.WindRiver.com
     \_ V      mailto:Michael.Scharf at gmx.de



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